US3158274A - Carrying ram, gate, and hydraulic control - Google Patents

Carrying ram, gate, and hydraulic control Download PDF

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Publication number
US3158274A
US3158274A US95776A US9577661A US3158274A US 3158274 A US3158274 A US 3158274A US 95776 A US95776 A US 95776A US 9577661 A US9577661 A US 9577661A US 3158274 A US3158274 A US 3158274A
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Prior art keywords
ram
gate
load
valve
gate member
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US95776A
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Ovie C Mensinger
Roger W Spencer
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Doosan Bobcat North America Inc
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Clark Equipment Co
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B66—HOISTING; LIFTING; HAULING
    • B66C—CRANES; LOAD-ENGAGING ELEMENTS OR DEVICES FOR CRANES, CAPSTANS, WINCHES, OR TACKLES
    • B66C19/00—Cranes comprising trolleys or crabs running on fixed or movable bridges or gantries
    • B66C19/005—Straddle carriers

Definitions

  • Straddle carriers have been in use for a considerable period in the lumber industry, the metal industry and elsewhere.
  • the conventional arrangement for handling material with such machines is to load the material to be transported on a bolster.
  • a bolster may consist of a rectangular frame or platform of wood or steel, which is arranged to support the material to be carried above it, and to be picked up by being engaged by the load hooks of the straddle carrier beneath and along the two longer sides of the rectangular frame.
  • Straddle carriers are provided with depending load hooks along the two sides of the machine just inside the wheels. These hooks are arranged for small lateral movement so that they may be moved apart to provide clearance as the carrier is driven over the bolster. After the carrier is in position over the bolster the hooks are moved inwardly beneath the bolster. Then the hooks may be raised vertically a sufiicient amount to raise the bolster with its load off of the ground and allow the bolster and the load to be transported to another location where they are set down again.
  • coils of metal strip and wire have generally been handled on bolsters in the same manner as other materials.
  • the handling of such coils with a straddle carrier in this manner is generally much more convenient and less costly than other methods of handling coils, however, if conventional bolsters are used it is necessary to load the coils onto the bolster before the straddle carrier can pick them up. Similarly, it is necessary to unload them from the bolster again at the end of the trip by the straddle carrier.
  • this previous load handling device is carried by the straddle carrier and the coils which the carrier is to pick up are arranged with the holes in the coils located coaxially so that the ram portion of the load handling device can enter the openings of all of the coils ing the load hooks so that the ram disengages the coils and then backing up the straddle carrier from the coils.
  • Another object is to provide a ram type coil handling device selectively supportable at one end and elevatable in a relatively unloaded condition regardless'of whether said one end is supported, and elevatable in a relatively loaded condition only when said one end is supported.
  • Still another object of the present invention is to provide in a load handling device of the elevatable ram type having ram support means movable into and out of engagement with the ram end means for locking the support means to the ram, improved control means for sequentially unlocking and disengaging the support means from the ram and sequentially engaging and locking the support means with the ram, plus interlocking control means for permittin elevation of a predetermined load on the device only when the support means engages and is locked to the ram.
  • FEGURE 1 is a view in perspective of the improved coil handling device in its operative carrying position upon a conventional straddle carrier which carrier is shown by dotted line representation;
  • FIGURE 2 is a view in perspective of the improved coil handling attachment shown apart from its connection with a straddle carrier;
  • FIGURE 3 is a fragmentary side elevational view showing the forward end of the improved coil handling apparatus with the pivotal gate member in its fully closed position; 7
  • FIGURE 4 is a front elevational view of the improved coil handling attachment; the view being taken substantially along the line 4-4 of FIGURE 3;
  • FIGURE 5 is a fragmentary side elevational view similar to FIGURE 3 showing the pivotal gate member in a partially open position;
  • FIGURE 6 is a front elevational view similar to FIG- o ea URE 4; the view being taken substantially along the line 66 of FIGURE
  • FIGURE 7 is a schematic hydraulic diagram showing the relationship of the various hydraulic components for actuating the improved coil handling apparatus.
  • FIGURE 8 is a schematic wiring diagram for illustrating the relationship and operation of the various electrical elements for the improved coil handling apparatus.
  • the carrier 10 includes a pair of side frame portions 12 which are interconnected by an overhead top portion (not shown) to form the gantry structure.
  • the machine 10 includes a pair of front dirigible wheels 14 and a pair of rear dirigible drive wheels 16 (only one of which appears in the drawing).
  • the machine is propelled by an internal combustion engine or other suitable prime mover which may be located in the compartment 18.
  • the prime mover actuates the rear drive wheels 16 by means of a chain drive mechanism or other equivalent drive means.
  • the front and rear dirigible wheels 14 and 16 are connected to and operated by a suitable operators steering wheel which is located in the operators compartment at the top of the vehicle.
  • the machine 10 includes a pair of lift or load hooks 17 which depend just inside the wheels adjacent the sides of the vehicle. These load hooks are arranged to be moved laterally in and out a small amount. They are also arranged to be raised and lowered in a manner well known in the art.
  • the hooks may be operated hydraulically both for their lateral movements and their vertical movements, or they may be operated by mechanical or other equivalent means if desired, all of which is well known in the art.
  • the power for operating the hooks ordinarily is derived from the same prime mover which propels the vehicle 10.
  • the load handling device of the present invention is shown in position on the straddle carrier in FTGURE l and removed from the carrier in FIGURE 2 and is designated generally by the numeral 29.
  • the device 20 includes a pair of longitudinally extending frame or stringer members 22 which are arranged in parallel relation and are located so that they may be supported from and above the load hooks 17.
  • the stringer members 22 are provided with downwardly projecting leg members 24 adjacent each end thereof which are engaged by the load hooks 17. Also, the leg members 24 rest on the ground or other supporting surface and maintain the stringer members 22 substantially above such surface so that the load hooks may enter beneath the stringer members to enable the carrier to pick up the load handling device.
  • the load handling device 26 further includes a transverse brace member 26 which is connected between the stringer members 22 adjacent one end of the load handling device. Secured to the brace member 26 on opposite sides thereof as illustrated, are a pair of depending substantially triangular plates 28 which form with the brace member a rigid inverted pyramidal structure. Adjacent the apex of the inverted pyramid a longitudinally extending ram member 30 is connected.
  • the ram 36 is preferably formed of a hollow steel tube which extends longitudinally forwardly from the brace member 26 midway between the stringer members 22 and in parallel relation with the stringer members.
  • the ram 30 has a tapered nose portion 32 at the foward end (see FIG- URES 3 and 5) to facilitate the entry of the ram into coils of metal strip and wire and the like.
  • the load handling device further includes a transverse brace member 34 secured to upturned extensions 36 of the stringer members 22. Suitable strengthening gusset plates 38 are provided at the juncture at each end of the brace member 34 where it joins with the respective stringer 22.
  • the brace members 26 and 34, and the plates 28 and 38 are all welded solidly to their respective joining elements and to the stringer members 22 to form a rigid unitary structure.
  • the load handling device 20 of the present invention includes a pivotally hinged gate member generally indicated at 49.
  • the gate member d0 generally comprises a pair of diagonally extending frame members 42 and 44 having ends which join together and terminate adjacent the nose portion 32 of the ram when the gate member is closed.
  • the frame members 42 and 44 are braced intermediate their ends by means of a transversely extending brace member 43 and are secured together adjacent the nose of the ram by means of a gusset plate 45.
  • the opposite ends of these frame members 42 and 44 are each provided with a sleeve member 46 secured thereto conveniently by welding.
  • the sleeve members 46 are keyed to, or otherwise secured to, shafts 48 extending therethrough.
  • the shafts 48 extend laterally outwardly from the sleeves 46 where they are journaled in bearing members 50 which are rigidly secured to the gusset plates 38. Approximately midway of their lengths each of the shafts 48 are provided with sprockets 52 which are rigidly keyed thereto and are adapted to be driven by a chain 54 which is in turn driven by a sprocket 56 secured to a shaft 58. The sprockets and chains are enclosed by suitable cover members 57 for safety reasons and to keep foreign particles out of the drive means.
  • the shafts 58 are journaled adjacent their outboard ends within suitable hearing members 6% which arerigidly secured to the transverse brace member 324.
  • Theshafts 58 at their inboard ends are suitably coupled to the output shaft 62. of a reversible hydraulic motor generally indicated at @4- which, through the mechanism above described, is adapted to selectively move the gate member 40 into and out of engagement with the nose portion 32 of the ram 30.
  • the operation and control of the hydraulic motor 64 will be more fully described presently.
  • a collar 66 secured to the gusset plate 45.
  • An aperture 68 extends through the collar 66 and the gusset plate 45 and is adapted to register with a stubshaft '74 rigidly secured to the ram 3 and projecting outwardly therefrom.
  • the aperture 68 and the stub-shaft 7d are suitably formed as shown so as to have a substantially close sliding fit with one another as the gate member 4% is pivotally moved into and out of engagement with the ram 38.
  • the stub-shaft 70 is provided on the upper portion thereof toward its outboard end with a cut out notch 72 (FIGURE 5).
  • Pivotally connected to the collar member 66 as at 74 is a triangular shaped locking plate '76.
  • the locking plate 76 is adapted to be pivoted so as to register with the notch '72 in the stubshaft 7% to thereby securely connect the gate member 44 ⁇ to the ram 39.
  • a yoke member 78 Pivotally connected to one corner of the locking plate 76 is a yoke member 78 which in turn is attached to one end of the actuating shaft 80 of a double-acting hydraulic cylinder 82.
  • the cylinder 82 is pivotally connected to the frame member 42 by means of a yoke member 34 and a supporting bracket 86. Movement of'the actuating shaft 8t) under the control of the cylinder 82 causes the locking plate 76 to be moved into the locking and unlocking positions as shown in FIGURES 3 and S. The control of the cylinder 82 to accomplish such movement will be described presently.
  • FIGURE 7 illustrates diagrammatically a form of hydraulic circuit which may be employed in connection with the present invention.
  • the prime mover of the straddle carrier 10 is designated by the reference numeral 88.
  • the prime mover 88 Connected to be driven by the prime mover 88 are a pair of positive displacement pumps 9t and 92 of suitable and Well known type.
  • intake conduits 94 and 96 connect, respectively, the pumps 90 and 92 with a suitable reservoir or sump 98 containing the hydraulic fluid for the system.
  • Anoutlet conduit 19% connects the pump 91 to a suitable manually operated control valve 1tl2 of well known type for selectively controlling the operation of 'a pair of double-acting hydraulic motors 11M and 1116 which are connected to the load hooks of the straddle carrier 16 for raising and lowering same as desired and in a manner well known in the art and to which the coil handling attachment 21) is connected for operation as above described.
  • An outlet conduit 10% connects the pump 2 to a suitably mmually operable control valve 110 which is of the same general type as the control valve 1%2 and is adapted to selectively connect the reversible rotary hydraulic motor 64 and the double-acting cylinder 82 into the circuit for pivoting the gate member 49 and locking same into position on the ram 33 as above described.
  • a suitable pressure relief valve 1139 of well known type is provided in the conduit 1% to relieve excessive pressures.
  • the control valve 111 as shown in the diagram, is in a neutral position. When in this position, oil flow from the pump 92 is by-p-assed through the valve 11% to the sump $8.
  • the gate member 4'1) is in its full open position and that the ram 30 has been loaded with a quantity of coils for transporting from one location to another in the manner described in the previously mentioned patent. in accordance with the present invention it is now desired to have the gate member 461 pivot to its closed position and be locked therein to the ram 36.
  • the control valve 110 is provided with an operating lever 112 which may be selectively moved from the neutral position to two diiierent operating positions which shall be herein designated as gate open and gate close positions.
  • an operating lever 112 When the operating lever is moved into the gate close position the conduit 168 will be con nected through the valve 110 to a conduit 114 which leads to a sequence and check valve of suitable type and generally designated at 116.
  • the valve 116 controls the sequence of oil flow from the conduit 114 through a pair of conduits 113 and 120 by pressure rise within the valve.
  • Valves of this type are well-known in the art and a detailed description thereof is not believed to be necessary herein.
  • An example of one type of valve suitable for operation in the present circuit is one manufactured by Vickers Incorporated under their model number RCT-03-D2.
  • valve 115 is constructed to operate such that oil flow entering the pressure inlet 115 is directed into the conduit 118 to the rotary hydraulic motor 64 so as to cause a counterclockwise rotation thereof as viewed in the diagram, and is blocked from entering the conduit 121 until the pressure conducted through a passage 117 overcomes an adjustable valve spring 119 to move a piston 125 therein. Full pressure is then available at a secondmy outlet to the conduit 120.
  • Reverse free flow through the valve is provided by means of a spring loaded one-way check valve 127 therein which connects the conduits 118 and 126
  • a spring loaded one-way check valve 127 therein which connects the conduits 118 and 126
  • the sequence valve 116 will then operate to cause fluid under pressure to be admitted into the left hand end of the double-acting hydrauiic cylinder 32 which will impart a movement to the actuating shaft 8d to thereby cause the locking plate 76 to be moved into engagement with the slot 72 in the stub-shaft 711 on the ram 30 as previously described.
  • the cylinder 52 is being actuated as above described, the right hand end thereof is connected to the reservoir or sump 9% by means of a conduit 122, a sequence valve generally indicated at 124-, a conduit 126, suitable connections through the valve and a drain conduit 128.
  • the outlet side of the motor 64 is also connectedto the sump at this time by means to be described presently.
  • a suitable pilot check valve 121 is connected in parallel with the conduits 121i and '122'by means of a conduit 123 to prevent reverse flow through the cylinder 82 in the event of seepage through the rotary hydraulic motor 64.
  • the conduit 123 serves as a pilot line to release the check valve 121 when reverse flow under pressure is desired, as will appear presently.
  • valve 11% When the valve 11% is actuated to the gate open position by means of a shifting of the operating lever 112, the conduit 1118 will be connected through the valve 111? to the conduit 126 and pressure fluid will be directed through the sequence valve 124 (which is identical to the valve 116) to the conduit 122 and into the right hand end of the double-acting hydraulic cylinder 82. The pressure fluid will also be directed through the conduit 123 to release check valve 121 as above mentioned. The pressure fluid entering the cylinder 82 will result in a movement of the actuating shaft 8% so as to unlock the locking plate 76 as should now be apparent.
  • the sequence valve 124 When the cylinder 82 has completed the unlocking stroke, the sequence valve 124 will be actuated to cause the pressure fluid to flow through a conduit 131) into an adjustable counterbalance valve 132 and through a conduit 134 into the rotary hydraulic motor 64 causing it to rotate in a clockwise direction. Such rotation of the motor will, through the chain .and sprocket connections previously described, result in a movement of the gate member 40 into its fully open position.
  • an adjustable counterbalance valve 132 is interposed between the conduits 131) and 134 leading from the sequence valve 124 to the rotary hydraulic motor 64.
  • This counterbalance Valve 132 is similar to the sequence valves and is also of a type well-known in the art and a detailed description thereof is not deemed necessary herein. It should sufiice herein to point out that the valve 132 is provided for maintaining a back pressure to counteract the hydraulically sustained load of the gate member 4% to thereby prevent the weight of the gate member from causing it to fall too rapidly during the closing operation.
  • the metering orifice thus creates a back pressure during the closing operation to restrict the flow of fluid from the motor 64 to thereby counterbalance and compensate for the weight of the gate member 4b in order to prevent the gate member from closing too rapidly during the close operation.
  • the closing movement of the gate member is substantially limited to the speed at which the rotary hydraulic motor 64 drives same through the chain and sprocket drive means.
  • Interlocking control means is also provided in connection with the present invention to prevent lifting of the loaded coil carrying attachment 21) by the load hooks of the straddle carrier if the gate member 40 is not fully closed and locked into position against the ram 30.
  • a branch conduit 14% from the conduit 1011 leads to a main relief valve M2 connected in the circuit to the load hook actuating hydraulic motor 1% and 1% previously described.
  • This relief valve 142 serves the conventional function of relieving excessive pressures in the circuit and for bypassing the pressure fluid to the sump 98 when the motors 1M and 106 are not operating or at such times as the motors have been actuated and are at their fully extended positions.
  • a solenoid operated valve 144 Attached to the vent connection of relief valve 142 by means of a suitable conduit 1&3 is a solenoid operated valve 144.
  • the solenoid operated valve 144 is of the normally open type and is closed by energization of a solenoid 1 26 under the control of a gate switch 185 to be presently described.
  • a remote or secondary relief valve 154 is connected in series with the main relief valve and the solenoid valve 144 by means of a suitable conduit 152.
  • the main relief valve 142 is normally set to relieve pressures in excess of, for example, 1450 pounds per square inch.
  • the vent connection on this relief valve 142 provides for the series connection with the secondary relief valve 151) through the solenoid operated valve 144 to in effect reduce the operating pressure of the main relief valve 142 as will appear presently. Since the solenoid operated valve 144 is normally open, the secondary relief valve 150 is normally operative.
  • the switch 185 generally consists of a housing 192 having a pair of stationary electrical contacts shown at 194 secured thereto.
  • a spring loaded switch plunger 196 is mounted for reciprocating movement within the housing 192 and carries thereon a conductor 198 which is adapted to bridge the gap and complete an electrical connection through the contacts 194.
  • the plunger 196 is biased to assume the position shown in FIGURE 6 wherein the conductor 198 is out of engagement with the contacts 194, thus as above mentioned it is a normally open switch.
  • the gate switch 185 is open which results in de-energization of the solenoid 146 causing the valve 144 to remain open. This in turn results in an opening of the hydraulic circuit to the secondary relief valve 150.
  • the secondary relief valve is set to operate so as to relieve pressures in excess of, for example, 250 pounds per square inch. This low pressure relief permits picking up the coil ram attachment without load. If, however, there were coils in position on the ram 30, and the gate member 49 were not fully closed, the coil ram attachment 21 could not be raised because of insufficient pressure.
  • the aforementioned arrangement provides a safety feature which serves to prevent damage to the ram 30.
  • FIGURE 8 which illustrates diagrammatically an electrical circuit suitable for operation of the mechanism of the present invention; it may be seen that electrical power to energize the circuits shown is obtained from a battery 162 which may be in the ignition system for the prime mover 88 of the straddle carrier it
  • the battery 162 is conventionally grounded as at 164 and is connected at the other or hot side to a pressure switch 166 by means of a conductor 168.
  • the pressure switch 166 is not an essential element'in the circuit, but is here shown inasmuch as it does serve dual useful purposes.
  • the switch is of conventional type and need not be described fully herein.
  • An example of a commercially available switch of this type is one manufactured by John W.
  • a conventional fuse block 170 may also, but not necessarily, be placed in the circuit in series with the pressure switch 166.
  • the indicator light 172 may, for example, be a green light and when lighted as hereinafter described will indicate a safe operating condition.
  • the indicator light 174 may, for example, be a red light and when lighted as hereinafter described will indicate an unsafe operating condition.
  • the indicator light 172 is herein used to indicate that the gate member 40 is closed and locked, and that, therefore the unit is safe for operation. Current for the light 172 flows from the fuse block 170 through a conductor 176 to one terminal of the light socket.
  • the other terminal of the light socket is connected by means of a conductor 178 to one terminal 180 of a three terminal plug-in connector generally indicated by the numeral 182.
  • the plug-in connection of the connector 182 is normally made when the coil carrying attachment 26 is to be used with a straddle carrier in accordance with the previous description.
  • a conductor 184 leads from the terminal 180 to one side of the gate switch 185.
  • the gate switch 185 is connected in series, by means of a conductor 186 to one side of a lock switch 188, the other side of which is grounded to the frame as indicated at 190.
  • a second gate switch 148 is provided which is similar in construction to the previously described gate switch 185 except that whereas the switch 185 is normally open, the switch 148 is normally closed. That is, when the gate member 41 is in its open position, as shown in FIGURE 6 the gate switch 148 is closed.
  • the switch generally consists of a housing 154 having a pair of stationary contacts 156 secured thereto.
  • a spring loaded switch plunger 158 is mounted for reciprocating movement within the housing 154 and carries thereon a conductor 16!) which is adapted to bridge the gap and complete an electrical connection through the contacts 156.
  • the plunger 158 is biased to assume the position shown in FIGURE 6 wherein the conductor 166 is in engagement with the contacts 156, thus as above mentioned it is a normally closed switch.
  • the gate switch 185 and the lock switch 188 are connected in series in the circuit.
  • the lock switch 188 is also of the normally opened type.
  • the lock switch 138 is attached to the gate member 40 and is arranged so as to be actuated by an abutment member 20! which may be mounted upon or arranged to be moved upon movement of the locking plate 76 so that when the locking plate 76 is moved to its locking position as seen in FIGURE 4, the plunger of the switch is depressed so as to close the circuit therethrough.
  • the indicator light 174 receives current from the fuse block 170, in the same manner as the indicator light 172, by means of a jumper conductor 202 between the two lights.
  • the other connection to the indicator light 174 is through a conductor 204 to a terminal 206 of the plugin connector 182.
  • a conductor 298 leads from the terminal 206 to one side of the gate switch 148 (previously described), the other side of which is suitably grounded to the frame as indicated at 216.
  • the solenoid 146 which operates the solenoid valve 144 is connected in parallel with the safe indicator light 172 by means of a pair of conductors 212 and 214.
  • the gate switch 185 is of the normally opened type. When the gate member 40 is not fully closed, the switch 185 is opened, therefore, the green indicator light 172 will not be illuminated and also the solenoid 146 will be de-energized. It should be noted also that the red indicator light 174 will be illuminated at all times, except when the gate member 49 is fully closed, and thereby would indicate an unsafe operating condition.
  • the plug-in connector 182 is provided with a third terminal 215.
  • a conductcr 218 Leading from the terminal 216 is a conductcr 218 which is suitably grounded as at 220 to the frame of the straddle carrier 10.
  • Another conductor 222 leads from the terminal 216 and is suitably grounded as at 224 to the coil carrying attachment 20. The pur pose of these conductors 218 and 222 is to make certain of a positive ground connection between the attachment and the carrier frame.
  • straddle carrier equipped with the improved coil handling attachment picks up a load of coils of metal or wire, transports them, and deposits them at the destination, all without the assistance of a helper on the ground.
  • the operator in the straddle carrier performs all operations from within the cab merely by selecting and manipulating in the proper sequence a plurality of control elements.
  • the straddle carrier 10 is first maneuvered into a position such that the ram 30 is positioned adjacent one end or" a series of coils of wire and is aligned such that the axis of the ram 31 is parallel with and above an axis through the openings in the coils.
  • the operator manipulates the operating lever of the valve 102 to cause the load hooks to lower the coil handling attachment until the ram is positioned coaxially with the coils.
  • the straddle carrier 11 is then moved forwardly such that the ram 30 passes through the series of coils and projects outwardly through the opposite end thereof.
  • the operating lever 112 of the valve 119 is then manipulated into the gate close position and the rotary hydraulic motor 64 will thus be operated to close the gate member 49 over the end of the ram 30.
  • the sequence valve 116 will automatically cause the hydraulic cylinder 82 to then be actuated to engage the locking plate 76 into position within the slot 72 in the stub shaft 70 on the ram 30.
  • the closing movement of the gate member 40 will close the circuit through the gate switch 185 and open the circuit through the gate switch 148.
  • the opening of the circuit through the gate switch 143 opens the circuit through the red indicator light 174.
  • the operator then manipulates the operating lever of the control valve 102 to cause the cylinders 104 and 106 to be actuated to raise the load hooks and thus the coil handling attachment 20.
  • the straddle carrier 10 may then be driven to the unloading destination.
  • the gate member 40 is securely locked into position over the end of the ram 30, there is provided a rigid structural support for the loaded ram and the straddle carrier can be driven over rough surfaces or forwardly down inclined ramps Without danger of any of the coils becoming disengaged from the ram 30.
  • the operator manipulates the operating lever of the control valve 102 to cause the cylinders 104 and 106 to be actuated to lower the load hooks to a position such that the coils are supported on the ground or other supporting surface.
  • the operating lever 112 of the control valve is then manipulated to the gate open posi tion thereby rendering the sequence valve 124 eifective to cause the cylinder 82 to be actuated to disengage the locking plate 76 from the ram.
  • the sequence valve then automatically causes the rotary hydraulic motor 64 to be operatedto pivot the gate member/t0 to its full open position.
  • the straddle carrier 10 may then be backed away from the series of cells thereby withdrawing the ram 31) and the carrier is then in condition to pick up an additional load if desired.
  • a material handling device comprising frame means, a ram member secured at one end to said frame means, gate means supported from said frame means and movable between open and closed positions relative to the other end of said ram member, elevator means for raising said frame means, and control means operatively connected to said elevator means providing in said elevator means a relatively large load lifting capacity when said gate means is in its closed position and a relatively small load lifting capacity when said gate means is in its open position.
  • a material handling device comprising frame means, a cantilever ram member secured at one end to said frame means, gate means supported from said frame means and actuatable between supporting and non-supporting positions relative to the free end of said ram member, load lifting means for raising and lowering said frame means, and interlocking control means operatively connected to said load lifting means and to said gate means for providing said load lifting means with a relatively large load lifting capacity when said gate means is in supporting position and with a relatively small load lifting capacity when said gate means is in its nonsupporting position.
  • a portable load handling device for use with a straddle carrier or the like having load hooks and means normally operable to elevate the load hooks, comprising a load supporting frame adapted to be engaged and elevated by the load hooks, a load engaging cantilever ram member secured at one end to said frame, a gate member pivotally attached to said frame adjacent the unsup ported end of said ram member for opening and closing movement relative thereto, drive means for opening and closing said gate member, locking means for securing said gate member when closed to said ram member, sequential control means for effecting sequential operation of said drive means and said locking means during opening and closing of said gate member, and interlocking control means responsive to the position of said gate member for preventing elevation of said load hooks when said load hooks support thereon more than a predetermined load and the said gate member is open and permitting eleva tion of said load hooks when said load hooks support thereon more than said predetermined load and the said gate member is closed.
  • a load handling device comprising frame means adapted to be engaged by the load lifting means, an elongated ram member having one end secured to said frame means, a gate member secured to said frame means adjacent the normally unsupported end of said ram member and ac tuatable into open and closed positions relative to the urn supported end of said ram member for supporting said normally unsupported end when in a closed position, and interlocking control means operatively connected to the load lifting means and to the gate member for providing in the load lifting means a first load lifting capacity when said gate member is open and the second load lifting capacity which is more than the said first load lifting capacity when said gate member is closed.
  • a load handling device comprising frame means, a cantilever ram member secured to said frame means, a gate member secured to said frame means adjacent the unsupported end of said ram member and actuatable be tween open and closed positions relative to the unsup ported end of said ram member, a fluid pressure system comprising fluid drive means operatively associated with said gate member for actuating said gate member between its open and closed positions, fluid actuated means for securing said gate member in its closed position to said ram member, a main control valve for selectively directing fluid flow through said system in a first or second direction or diverting fluid flow from said system, fluid sequence control means, said control means comprising a first sequence valve connected to said main control valve for causing fluid flowing in said first direction to be directed first to said drive means and then to said securing means and a second sequence valve connected to said main control valve for causing fluid flowing in said second direction to be directed first to said securing means and then to said drive means, fluid lifting means for selectively raising and lowering said frame means, and
  • a material handling device comprising frame means, a cantilever ram member secured to said frame means, a gate member secured to said frame means adjacent the unsupported end of said ram member and actuatable between open and closed positions relative to the unsupported end of said ram member, fluid pressure actuated means for selectively raising and lowering said frame means, and control means operatively connected to said fluid pressure actuated means providing therefor a relatively high load lifting capacity when said gate member is in its closed position and a relatively low load lifting capacity when said gate member is in its open position, said control means including relatively high and low pressure responsive valve means, and other valve means responsive to the open and closed positions of said gate member for operatively connecting said high pressure valve means with said pressure actuated means when said gate member is in one position and said low pressure valve means with said pressure actuated means when said gate member is in the other position.
  • a material handling device comprising frame means, a cantilever ram member secured to said frame means, a gate member secured to said frame means adjacent the unsupported end of said ram member and actuatable between open and closed positions relative to the unsupported end of said ram member, fluid pressure actuated means for selectively raising and lowering .said frame means, and control means operatively connected to said fluid pressure actuated means providing therefor a relatively high load lifting capacity when said gate member is in its closed position and a relatively low load lifting capacity when said gate member is in its open position, said control means including a relatively high pressure relief valve, a relatively low pressure relief valve, two position valve means arranged to selectively connect said high and low pressure relief valves to said pressure actuated means, and switch means operatively connected to said two position valve means and responsive to the position of said gate member, said switch means and two position valve means being arranged to connect said high pressure relief valve to said pressure actuated means when said gate member is closed and said low pressure valve means to said pressure actuated means when said gate member is
  • the combination comprising supporting frame means, an elongated cantilever ram'member attached to said frame means, a gate member connected to said frame means adjacent the unsupported end of said ram member and actuatable between open and closed positions relative to the unsupported end of said ram member, fluid pressure actuated load means for elevating said frame means, a fluid system including means for selectively locking and unlocking said gate member in its closed position to said ram .member, fluid motor means connected to said gate memher for opening and closing said gate member, first valve means for causing pressure fluid to be directed first to said fluid motor means and then to said locking means for closing of the gate member and second valve means for causing pressure fluid to be directed first to said locking means and then to said fluid motor means for opening of the gate member, and interlocking control means operatively connected to said load means and to said gate member providing a relatively large load lifting capacity of said load means when said gate member is closed andlocked and a relatively small lifting capacity when said gate is unlocked and open, said control

Description

Nov. 24, 1964 o. c. MENSINGER ETAL CARRYING RAM, GATE, AND HYDRAULIC CONTROL 5 Sheets-Sheet 1 Original Filed June 16, 1958 INVENTORS. C. MENSINGER W. SPENCER OVIE ROGER Nov. 24, 1964 o. c. MENSlNGER ETAL 3,158,274
CARRYING RAM, GATE, AND HYDRAULIC CONTROL Original Filed June 16, 1958 5 Sheets-Sheet 2 ATTY.
Nov. 24, 1964 o. c. MENSINGER ETAL 3,153,274
CARRYING RAM, GATE, AND HYDRAULIC CONTROL Original Filed June 16, 1958 5 Sheets-Sheet 3 INVENTORS. OVIE C. MENSINGER ROGER W. SPENCER ATTY.
Nov. 24, 1964 o. c. MENSINGER ETAL 3,158,274
CARRYING RAM, GATE, AND HYDRAULIC CONTROL Original Filed June 16, 1958 5 Sheets-Sheet 4 FIG. 7
.INVENTORS MENSINGER BY ROGER W. SPENCER OVIE ATTY.
Nov. 24, 1964 o. c. MENSINGER ETAL 3,158,274
CARRYING RAM, GATE, AND HYDRAULIC CONTROL Griginal Filed June 16, 1958 5 Sheets-Sheet 5 INVENTORS. MENSINGER OVIE C ROGER W. SPENCER a 8 Y B ATTY.
United States Patent O "we 3,158,274 CARRYING RAM, GATE, AND HYlEl-RAULHQ NTRL This invention relates to load handling devices for straddle carriers or gantry trucks as they are sometimes called, and particularly to a load handling device which will facilitate the handling of coils of metal in strip form,
coils of wire and the like.
This application is a continuation of application Serial No. 742,164, filed June 16, 1958, now abandoned.
Straddle carriers have been in use for a considerable period in the lumber industry, the metal industry and elsewhere. The conventional arrangement for handling material with such machines is to load the material to be transported on a bolster. Such a bolster may consist of a rectangular frame or platform of wood or steel, which is arranged to support the material to be carried above it, and to be picked up by being engaged by the load hooks of the straddle carrier beneath and along the two longer sides of the rectangular frame.
Straddle carriers are provided with depending load hooks along the two sides of the machine just inside the wheels. These hooks are arranged for small lateral movement so that they may be moved apart to provide clearance as the carrier is driven over the bolster. After the carrier is in position over the bolster the hooks are moved inwardly beneath the bolster. Then the hooks may be raised vertically a sufiicient amount to raise the bolster with its load off of the ground and allow the bolster and the load to be transported to another location where they are set down again.
Heretofore, coils of metal strip and wire have generally been handled on bolsters in the same manner as other materials. The handling of such coils with a straddle carrier in this manner is generally much more convenient and less costly than other methods of handling coils, however, if conventional bolsters are used it is necessary to load the coils onto the bolster before the straddle carrier can pick them up. Similarly, it is necessary to unload them from the bolster again at the end of the trip by the straddle carrier.
US. Patent No. 2,975,922, dated March 21, 1961, and issued in the name of Raymond A. Dodge, discloses a load handling device which includes a pair of stringer members located in parallel spaced apart relation which are adapted to be engaged by the load hooks of a straddle carrier. Brace means interconnect the stringer members at one end thereof, and a ram member is cantilevered from the brace means and extends centrally of and above the stringer members.
In operation, this previous load handling device is carried by the straddle carrier and the coils which the carrier is to pick up are arranged with the holes in the coils located coaxially so that the ram portion of the load handling device can enter the openings of all of the coils ing the load hooks so that the ram disengages the coils and then backing up the straddle carrier from the coils.
3,158,234 Patented Nov. 24, 1964 The present invention constitutes an improvement upon the above-described apparatus. By reference to the abovementioned patent it may be seen that the ram member is supported at only one end thereof which requires a sturdy structure to prevent damage thereto when loaded. Also, since the ram is open at the oneend when loaded it would be possible under certain conditions of operation and in maneuvering the straddle carrier over rough or downwardly inclined surfaces for one or more coils to become disengaged from the ram.
With the foregoing in mind, it is a primary object of the present invention to provide a coil handling device of the cantilever ram type wherein during load carrying operations improved means is provided for closing and supporting the ram at the normally open end thereof.
Another object is to provide a ram type coil handling device selectively supportable at one end and elevatable in a relatively unloaded condition regardless'of whether said one end is supported, and elevatable in a relatively loaded condition only when said one end is supported.
It is a further object to provide an elevatable coil handling device of the cantilever ram type having a pivoted gate member at one end thereof which may be unlocked from and pivoted outwardly of the ram for loading and closed over and locked to the open ram end for supporting the same during load carrying operations, and improved gate control means for controlling sequentially the movement and the locking of the gate member.
Still another object of the present invention is to provide in a load handling device of the elevatable ram type having ram support means movable into and out of engagement with the ram end means for locking the support means to the ram, improved control means for sequentially unlocking and disengaging the support means from the ram and sequentially engaging and locking the support means with the ram, plus interlocking control means for permittin elevation of a predetermined load on the device only when the support means engages and is locked to the ram.
It is a further object of the present invention to provide in a coil handling device improved control means for controlling remotely means disposed to support the open end of the device.
It is a further object of the present device to provide in a cantilevered type load handling device having means selectively securable to the open end thereof improved interlocking control means to prevent lifting of a load prior to securing the securable means to the open end of the device.
Other objects and advantages of the present invention will become readily apparent from the following detailed description of one illustrative embodiment thereof shown in the accompanying drawings wherein:
FEGURE 1 is a view in perspective of the improved coil handling device in its operative carrying position upon a conventional straddle carrier which carrier is shown by dotted line representation;
FIGURE 2 is a view in perspective of the improved coil handling attachment shown apart from its connection with a straddle carrier;
FIGURE 3 is a fragmentary side elevational view showing the forward end of the improved coil handling apparatus with the pivotal gate member in its fully closed position; 7
FIGURE 4 is a front elevational view of the improved coil handling attachment; the view being taken substantially along the line 4-4 of FIGURE 3;
FIGURE 5 is a fragmentary side elevational view similar to FIGURE 3 showing the pivotal gate member in a partially open position;
FIGURE 6 is a front elevational view similar to FIG- o ea URE 4; the view being taken substantially along the line 66 of FIGURE FIGURE 7 is a schematic hydraulic diagram showing the relationship of the various hydraulic components for actuating the improved coil handling apparatus; and
FIGURE 8 is a schematic wiring diagram for illustrating the relationship and operation of the various electrical elements for the improved coil handling apparatus.
Referring now to the drawings and particularly to FIGURE 1, there is illustrated by dotted line representation and indicated generally by the numeral it), a straddle carrier or gantry truck of the type with which the present load handling device may be used advantageously. The carrier 10 includes a pair of side frame portions 12 which are interconnected by an overhead top portion (not shown) to form the gantry structure. The machine 10 includes a pair of front dirigible wheels 14 and a pair of rear dirigible drive wheels 16 (only one of which appears in the drawing). The machine is propelled by an internal combustion engine or other suitable prime mover which may be located in the compartment 18. The prime mover actuates the rear drive wheels 16 by means of a chain drive mechanism or other equivalent drive means. The front and rear dirigible wheels 14 and 16 are connected to and operated by a suitable operators steering wheel which is located in the operators compartment at the top of the vehicle.
The machine 10 includes a pair of lift or load hooks 17 which depend just inside the wheels adjacent the sides of the vehicle. These load hooks are arranged to be moved laterally in and out a small amount. They are also arranged to be raised and lowered in a manner well known in the art. The hooks may be operated hydraulically both for their lateral movements and their vertical movements, or they may be operated by mechanical or other equivalent means if desired, all of which is well known in the art. The power for operating the hooks ordinarily is derived from the same prime mover which propels the vehicle 10.
The load handling device of the present invention is shown in position on the straddle carrier in FTGURE l and removed from the carrier in FIGURE 2 and is designated generally by the numeral 29. The device 20 includes a pair of longitudinally extending frame or stringer members 22 which are arranged in parallel relation and are located so that they may be supported from and above the load hooks 17. The stringer members 22 are provided with downwardly projecting leg members 24 adjacent each end thereof which are engaged by the load hooks 17. Also, the leg members 24 rest on the ground or other supporting surface and maintain the stringer members 22 substantially above such surface so that the load hooks may enter beneath the stringer members to enable the carrier to pick up the load handling device.
The load handling device 26 further includes a transverse brace member 26 which is connected between the stringer members 22 adjacent one end of the load handling device. Secured to the brace member 26 on opposite sides thereof as illustrated, are a pair of depending substantially triangular plates 28 which form with the brace member a rigid inverted pyramidal structure. Adjacent the apex of the inverted pyramid a longitudinally extending ram member 30 is connected. The ram 36 is preferably formed of a hollow steel tube which extends longitudinally forwardly from the brace member 26 midway between the stringer members 22 and in parallel relation with the stringer members. The ram 30 has a tapered nose portion 32 at the foward end (see FIG- URES 3 and 5) to facilitate the entry of the ram into coils of metal strip and wire and the like.
At its forward end, the load handling device further includes a transverse brace member 34 secured to upturned extensions 36 of the stringer members 22. Suitable strengthening gusset plates 38 are provided at the juncture at each end of the brace member 34 where it joins with the respective stringer 22. Preferably, the brace members 26 and 34, and the plates 28 and 38 are all welded solidly to their respective joining elements and to the stringer members 22 to form a rigid unitary structure.
The load handling device 20 of the present invention includes a pivotally hinged gate member generally indicated at 49. The gate member d0 generally comprises a pair of diagonally extending frame members 42 and 44 having ends which join together and terminate adjacent the nose portion 32 of the ram when the gate member is closed. The frame members 42 and 44 are braced intermediate their ends by means of a transversely extending brace member 43 and are secured together adjacent the nose of the ram by means of a gusset plate 45. The opposite ends of these frame members 42 and 44 are each provided with a sleeve member 46 secured thereto conveniently by welding. The sleeve members 46 are keyed to, or otherwise secured to, shafts 48 extending therethrough. The shafts 48 extend laterally outwardly from the sleeves 46 where they are journaled in bearing members 50 which are rigidly secured to the gusset plates 38. Approximately midway of their lengths each of the shafts 48 are provided with sprockets 52 which are rigidly keyed thereto and are adapted to be driven by a chain 54 which is in turn driven by a sprocket 56 secured to a shaft 58. The sprockets and chains are enclosed by suitable cover members 57 for safety reasons and to keep foreign particles out of the drive means. The shafts 58 are journaled adjacent their outboard ends within suitable hearing members 6% which arerigidly secured to the transverse brace member 324. Theshafts 58 at their inboard ends are suitably coupled to the output shaft 62. of a reversible hydraulic motor generally indicated at @4- which, through the mechanism above described, is adapted to selectively move the gate member 40 into and out of engagement with the nose portion 32 of the ram 30. The operation and control of the hydraulic motor 64 will be more fully described presently.
At the joint between the gate frame members 42 and 44 adjacent the nose portion 32 of the ram 30, there is provided a collar 66 secured to the gusset plate 45. An aperture 68 extends through the collar 66 and the gusset plate 45 and is adapted to register with a stubshaft '74 rigidly secured to the ram 3 and projecting outwardly therefrom. The aperture 68 and the stub-shaft 7d are suitably formed as shown so as to have a substantially close sliding fit with one another as the gate member 4% is pivotally moved into and out of engagement with the ram 38. To the end of positively locking the gate member 4%) to the ram 30, the stub-shaft 70 is provided on the upper portion thereof toward its outboard end with a cut out notch 72 (FIGURE 5). Pivotally connected to the collar member 66 as at 74 is a triangular shaped locking plate '76. When the gate member 40 is in the closed or carrying position as shown in FIGURE 3, the locking plate 76 is adapted to be pivoted so as to register with the notch '72 in the stubshaft 7% to thereby securely connect the gate member 44} to the ram 39. Pivotally connected to one corner of the locking plate 76 is a yoke member 78 which in turn is attached to one end of the actuating shaft 80 of a double-acting hydraulic cylinder 82. At its opposite end, the cylinder 82 is pivotally connected to the frame member 42 by means of a yoke member 34 and a supporting bracket 86. Movement of'the actuating shaft 8t) under the control of the cylinder 82 causes the locking plate 76 to be moved into the locking and unlocking positions as shown in FIGURES 3 and S. The control of the cylinder 82 to accomplish such movement will be described presently.
Referring now to FIGURES 7 and 8, the control means for operating the improved coil handling attachment 20 and the locking gate member 40 will now be described.
FIGURE 7 illustrates diagrammatically a form of hydraulic circuit which may be employed in connection with the present invention. In this diagram, the prime mover of the straddle carrier 10 is designated by the reference numeral 88. Connected to be driven by the prime mover 88 are a pair of positive displacement pumps 9t and 92 of suitable and Well known type. intake conduits 94 and 96 connect, respectively, the pumps 90 and 92 with a suitable reservoir or sump 98 containing the hydraulic fluid for the system.
Anoutlet conduit 19% connects the pump 91 to a suitable manually operated control valve 1tl2 of well known type for selectively controlling the operation of 'a pair of double-acting hydraulic motors 11M and 1116 which are connected to the load hooks of the straddle carrier 16 for raising and lowering same as desired and in a manner well known in the art and to which the coil handling attachment 21) is connected for operation as above described.
An outlet conduit 10% connects the pump 2 to a suitably mmually operable control valve 110 which is of the same general type as the control valve 1%2 and is adapted to selectively connect the reversible rotary hydraulic motor 64 and the double-acting cylinder 82 into the circuit for pivoting the gate member 49 and locking same into position on the ram 33 as above described. A suitable pressure relief valve 1139 of well known type is provided in the conduit 1% to relieve excessive pressures.
The control valve 111 as shown in the diagram, is in a neutral position. When in this position, oil flow from the pump 92 is by-p-assed through the valve 11% to the sump $8. Let it now be assumed that the gate member 4'1) is in its full open position and that the ram 30 has been loaded with a quantity of coils for transporting from one location to another in the manner described in the previously mentioned patent. in accordance with the present invention it is now desired to have the gate member 461 pivot to its closed position and be locked therein to the ram 36.
The control valve 110 is provided with an operating lever 112 which may be selectively moved from the neutral position to two diiierent operating positions which shall be herein designated as gate open and gate close positions. When the operating lever is moved into the gate close position the conduit 168 will be con nected through the valve 110 to a conduit 114 which leads to a sequence and check valve of suitable type and generally designated at 116. The valve 116 controls the sequence of oil flow from the conduit 114 through a pair of conduits 113 and 120 by pressure rise within the valve. Valves of this type are well-known in the art and a detailed description thereof is not believed to be necessary herein. An example of one type of valve suitable for operation in the present circuit is one manufactured by Vickers Incorporated under their model number RCT-03-D2. it should sufiice for the present disclosure tomerely point out that the valve 115 is constructed to operate such that oil flow entering the pressure inlet 115 is directed into the conduit 118 to the rotary hydraulic motor 64 so as to cause a counterclockwise rotation thereof as viewed in the diagram, and is blocked from entering the conduit 121 until the pressure conducted through a passage 117 overcomes an adjustable valve spring 119 to move a piston 125 therein. Full pressure is then available at a secondmy outlet to the conduit 120. Reverse free flow through the valve is provided by means of a spring loaded one-way check valve 127 therein which connects the conduits 118 and 126 From the foregoing description it should be apparent that when the valve 110 is actuated to the gate close position, the rotary hydraulic motor 64 will be operated to rotate in the counterclockwise direction throughout its full range of movement prior to the admission of fluid under pressure into the conduit 120. Such movement of the motor M, will by means of the chain and sprocket connection previously described, cause the gate member 6 40 to be pivoted to its closed position in engagement with the nose portion 32 of the ram 319.
When the motor 64 has completed its full range of movement as above described, the sequence valve 116 will then operate to cause fluid under pressure to be admitted into the left hand end of the double-acting hydrauiic cylinder 32 which will impart a movement to the actuating shaft 8d to thereby cause the locking plate 76 to be moved into engagement with the slot 72 in the stub-shaft 711 on the ram 30 as previously described. While the cylinder 52 is being actuated as above described, the right hand end thereof is connected to the reservoir or sump 9% by means of a conduit 122, a sequence valve generally indicated at 124-, a conduit 126, suitable connections through the valve and a drain conduit 128. The outlet side of the motor 64 is also connectedto the sump at this time by means to be described presently.
A suitable pilot check valve 121 is connected in parallel with the conduits 121i and '122'by means of a conduit 123 to prevent reverse flow through the cylinder 82 in the event of seepage through the rotary hydraulic motor 64.
. The conduit 123 serves as a pilot line to release the check valve 121 when reverse flow under pressure is desired, as will appear presently.
When the valve 11% is actuated to the gate open position by means of a shifting of the operating lever 112, the conduit 1118 will be connected through the valve 111? to the conduit 126 and pressure fluid will be directed through the sequence valve 124 (which is identical to the valve 116) to the conduit 122 and into the right hand end of the double-acting hydraulic cylinder 82. The pressure fluid will also be directed through the conduit 123 to release check valve 121 as above mentioned. The pressure fluid entering the cylinder 82 will result in a movement of the actuating shaft 8% so as to unlock the locking plate 76 as should now be apparent. When the cylinder 82 has completed the unlocking stroke, the sequence valve 124 will be actuated to cause the pressure fluid to flow through a conduit 131) into an adjustable counterbalance valve 132 and through a conduit 134 into the rotary hydraulic motor 64 causing it to rotate in a clockwise direction. Such rotation of the motor will, through the chain .and sprocket connections previously described, result in a movement of the gate member 40 into its fully open position.
As above mentioned, an adjustable counterbalance valve 132 is interposed between the conduits 131) and 134 leading from the sequence valve 124 to the rotary hydraulic motor 64. This counterbalance Valve 132 is similar to the sequence valves and is also of a type well-known in the art and a detailed description thereof is not deemed necessary herein. It should sufiice herein to point out that the valve 132 is provided for maintaining a back pressure to counteract the hydraulically sustained load of the gate member 4% to thereby prevent the weight of the gate member from causing it to fall too rapidly during the closing operation. During the opening operation of the gate member as above described, pressure fluid flowing from the conduit 139 through the valve 132, conduit 134. and into motor 64, passes through a restriction or metering orifice 135 in the valve 132. This restriction will result in a back pressure being created in the conduit between the valves 124 and 132. Such back pressure causes a one-way check valve 13% to be moved ofi its check valve 138 prevents direct communication between the conduits 134 and 1311 via the by-pass connection and all of the fluid must therefore pass through the metering orifice 136 into the conduit 13%, thence into the sequence valve 124, conduit LAB, valve 110 and drain conduit 128. The metering orifice thus creates a back pressure during the closing operation to restrict the flow of fluid from the motor 64 to thereby counterbalance and compensate for the weight of the gate member 4b in order to prevent the gate member from closing too rapidly during the close operation. Thus, the closing movement of the gate member is substantially limited to the speed at which the rotary hydraulic motor 64 drives same through the chain and sprocket drive means.
Interlocking control means is also provided in connection with the present invention to prevent lifting of the loaded coil carrying attachment 21) by the load hooks of the straddle carrier if the gate member 40 is not fully closed and locked into position against the ram 30. To this end, it should be noted that a branch conduit 14% from the conduit 1011 leads to a main relief valve M2 connected in the circuit to the load hook actuating hydraulic motor 1% and 1% previously described. This relief valve 142 serves the conventional function of relieving excessive pressures in the circuit and for bypassing the pressure fluid to the sump 98 when the motors 1M and 106 are not operating or at such times as the motors have been actuated and are at their fully extended positions. Attached to the vent connection of relief valve 142 by means of a suitable conduit 1&3 is a solenoid operated valve 144. The solenoid operated valve 144 is of the normally open type and is closed by energization of a solenoid 1 26 under the control of a gate switch 185 to be presently described. A remote or secondary relief valve 154 is connected in series with the main relief valve and the solenoid valve 144 by means of a suitable conduit 152.
The main relief valve 142 is normally set to relieve pressures in excess of, for example, 1450 pounds per square inch. The vent connection on this relief valve 142 provides for the series connection with the secondary relief valve 151) through the solenoid operated valve 144 to in effect reduce the operating pressure of the main relief valve 142 as will appear presently. Since the solenoid operated valve 144 is normally open, the secondary relief valve 150 is normally operative.
Referring briefly to FIGURES 3 to 6 inclusive, it may be seen that the gate switch 185, above mentioned,
is of the normally open type and is closed when the gate member 4!) is moved to its completely closed position as shown in FIGURES 3 and 4. The switch 185 generally consists of a housing 192 having a pair of stationary electrical contacts shown at 194 secured thereto. A spring loaded switch plunger 196 is mounted for reciprocating movement within the housing 192 and carries thereon a conductor 198 which is adapted to bridge the gap and complete an electrical connection through the contacts 194. When the gate member 49 is not completely closed, the plunger 196 is biased to assume the position shown in FIGURE 6 wherein the conductor 198 is out of engagement with the contacts 194, thus as above mentioned it is a normally open switch.
Referring now back to FIGURE 7, if the gate member 46 is not fully closed, the gate switch 185 is open which results in de-energization of the solenoid 146 causing the valve 144 to remain open. This in turn results in an opening of the hydraulic circuit to the secondary relief valve 150. The secondary relief valve is set to operate so as to relieve pressures in excess of, for example, 250 pounds per square inch. This low pressure relief permits picking up the coil ram attachment without load. If, however, there were coils in position on the ram 30, and the gate member 49 were not fully closed, the coil ram attachment 21 could not be raised because of insufficient pressure. The aforementioned arrangement provides a safety feature which serves to prevent damage to the ram 30.
Referring now to FIGURE 8 which illustrates diagrammatically an electrical circuit suitable for operation of the mechanism of the present invention; it may be seen that electrical power to energize the circuits shown is obtained from a battery 162 which may be in the ignition system for the prime mover 88 of the straddle carrier it The battery 162 is conventionally grounded as at 164 and is connected at the other or hot side to a pressure switch 166 by means of a conductor 168. The pressure switch 166 is not an essential element'in the circuit, but is here shown inasmuch as it does serve dual useful purposes. The switch is of conventional type and need not be described fully herein. An example of a commercially available switch of this type is one manufactured by John W. Hobbs Corporation, Division of tewart Warner Company, under their model MI-672. The pressure switch serves to eliminate additional and unnecessary current load on the ignition switch of an electrical system of this type and makes it possible to supply electricity to the accessory components only if the engine or prime mover is running; This then provides an automatic disconnect when the prime mover 88 is stopped. A conventional fuse block 170 may also, but not necessarily, be placed in the circuit in series with the pressure switch 166.
Mounted within the operators compartment of the straddle carrier 10, preferably on the instrument panel, or otherwise, are a pair of indicator lights 172 and 174. The indicator light 172 may, for example, be a green light and when lighted as hereinafter described will indicate a safe operating condition. The indicator light 174 may, for example, be a red light and when lighted as hereinafter described will indicate an unsafe operating condition. The indicator light 172 is herein used to indicate that the gate member 40 is closed and locked, and that, therefore the unit is safe for operation. Current for the light 172 flows from the fuse block 170 through a conductor 176 to one terminal of the light socket. The other terminal of the light socket is connected by means of a conductor 178 to one terminal 180 of a three terminal plug-in connector generally indicated by the numeral 182. The plug-in connection of the connector 182 is normally made when the coil carrying attachment 26 is to be used with a straddle carrier in accordance with the previous description. A conductor 184 leads from the terminal 180 to one side of the gate switch 185. The gate switch 185 is connected in series, by means of a conductor 186 to one side of a lock switch 188, the other side of which is grounded to the frame as indicated at 190.
A second gate switch 148 is provided which is similar in construction to the previously described gate switch 185 except that whereas the switch 185 is normally open, the switch 148 is normally closed. That is, when the gate member 41 is in its open position, as shown in FIGURE 6 the gate switch 148 is closed. Referring briefly to FEGURE 4, it may be seen that the switch generally consists of a housing 154 having a pair of stationary contacts 156 secured thereto. A spring loaded switch plunger 158 is mounted for reciprocating movement within the housing 154 and carries thereon a conductor 16!) which is adapted to bridge the gap and complete an electrical connection through the contacts 156. When the gate member 4t) is not completely closed, the plunger 158 is biased to assume the position shown in FIGURE 6 wherein the conductor 166 is in engagement with the contacts 156, thus as above mentioned it is a normally closed switch.
As above mentioned, the gate switch 185 and the lock switch 188 are connected in series in the circuit. The lock switch 188 is also of the normally opened type.
' Referring to FIGURES 4 and 6, it may be seen that the lock switch 138 is attached to the gate member 40 and is arranged so as to be actuated by an abutment member 20!) which may be mounted upon or arranged to be moved upon movement of the locking plate 76 so that when the locking plate 76 is moved to its locking position as seen in FIGURE 4, the plunger of the switch is depressed so as to close the circuit therethrough.
As previously described, the gate member 40 is moved into its closed position prior to the actuation of the locking plate 76. It therefore follows that the switches 185 and 183 will likewise be sequentially operated. It is important to note that because of the series connections of switches 185 and 188, both switches must be closed in order to establish a'circuit through the safe indicator light 172.
The indicator light 174 receives current from the fuse block 170, in the same manner as the indicator light 172, by means of a jumper conductor 202 between the two lights. The other connection to the indicator light 174 is through a conductor 204 to a terminal 206 of the plugin connector 182. A conductor 298 leads from the terminal 206 to one side of the gate switch 148 (previously described), the other side of which is suitably grounded to the frame as indicated at 216.
The solenoid 146 which operates the solenoid valve 144 is connected in parallel with the safe indicator light 172 by means of a pair of conductors 212 and 214.
As previously mentioned, the gate switch 185 is of the normally opened type. When the gate member 40 is not fully closed, the switch 185 is opened, therefore, the green indicator light 172 will not be illuminated and also the solenoid 146 will be de-energized. It should be noted also that the red indicator light 174 will be illuminated at all times, except when the gate member 49 is fully closed, and thereby would indicate an unsafe operating condition.
The plug-in connector 182 is provided with a third terminal 215. Leading from the terminal 216 is a conductcr 218 which is suitably grounded as at 220 to the frame of the straddle carrier 10. Another conductor 222 leads from the terminal 216 and is suitably grounded as at 224 to the coil carrying attachment 20. The pur pose of these conductors 218 and 222 is to make certain of a positive ground connection between the attachment and the carrier frame.
Having now described generally the structure of the elements making up the present invention together with the hydraulic control means and electrical circuitry for operating same; it is believed that the invention may be clarified and summarized by describing a typical operation wherein a straddle carrier equipped with the improved coil handling attachment picks up a load of coils of metal or wire, transports them, and deposits them at the destination, all without the assistance of a helper on the ground. The operator in the straddle carrier performs all operations from within the cab merely by selecting and manipulating in the proper sequence a plurality of control elements.
Let it be assumed for the following example that the gate member 49 is in its full open position and that the coil handling attachment 21) is elevated by the load hooks and that the straddle carrier is being maneuvered into position to pickup a load of coils of Wire.
The straddle carrier 10 is first maneuvered into a position such that the ram 30 is positioned adjacent one end or" a series of coils of wire and is aligned such that the axis of the ram 31 is parallel with and above an axis through the openings in the coils. The operator then manipulates the operating lever of the valve 102 to cause the load hooks to lower the coil handling attachment until the ram is positioned coaxially with the coils. The straddle carrier 11 is then moved forwardly such that the ram 30 passes through the series of coils and projects outwardly through the opposite end thereof.
The operating lever 112 of the valve 119 is then manipulated into the gate close position and the rotary hydraulic motor 64 will thus be operated to close the gate member 49 over the end of the ram 30. When the gate member has reached the fully closed position the sequence valve 116 will automatically cause the hydraulic cylinder 82 to then be actuated to engage the locking plate 76 into position within the slot 72 in the stub shaft 70 on the ram 30. The closing movement of the gate member 40 will close the circuit through the gate switch 185 and open the circuit through the gate switch 148. The opening of the circuit through the gate switch 143 opens the circuit through the red indicator light 174. The closing of the circuit through the gate switch 185 and the subsequent closing of the switch 188, by movement of the locking plate 76 into position, closes the circuit through the green indicator light 172 and also closes a the circuit to energize the solenoid 146 of the valve 144,
eliminating the series connection between the main relief valve 142 and the secondary relief valve 150, thereby making it possible for the cylinders 104 and 1% to be actuated to cause the load hooks to raise the coil han dling attachment 20 for transporting to the destination. The closing of the circuit through the green indicator light 172 indicates to the operator that .the unit is in a safe condition for transporting the load.
The operator then manipulates the operating lever of the control valve 102 to cause the cylinders 104 and 106 to be actuated to raise the load hooks and thus the coil handling attachment 20. The straddle carrier 10 may then be driven to the unloading destination. be noted that since the gate member 40 is securely locked into position over the end of the ram 30, there is provided a rigid structural support for the loaded ram and the straddle carrier can be driven over rough surfaces or forwardly down inclined ramps Without danger of any of the coils becoming disengaged from the ram 30.
When the unloading destination has been reached, the operator then manipulates the operating lever of the control valve 102 to cause the cylinders 104 and 106 to be actuated to lower the load hooks to a position such that the coils are supported on the ground or other supporting surface. The operating lever 112 of the control valve is then manipulated to the gate open posi tion thereby rendering the sequence valve 124 eifective to cause the cylinder 82 to be actuated to disengage the locking plate 76 from the ram. When the cylinder 82 has completed its full stroke, the sequence valve then automatically causes the rotary hydraulic motor 64 to be operatedto pivot the gate member/t0 to its full open position.
The straddle carrier 10 may then be backed away from the series of cells thereby withdrawing the ram 31) and the carrier is then in condition to pick up an additional load if desired.
While one illustrative embodiment of an improved coil handling attachment has been shown and described herein, it is obvious that various modifications may be made therein without departing from the spirit of the invention. To those skilled in the art of making mechanisms of the character described, many additional alterations and different embodiments and applications of this invention will suggest themselves without departing from the spirit and scope thereof. Therefore, the particular disclosure herein is intended to be illustrative only, and We do not intend to be limited thereto nor otherwise than by the terms of the appended claims.
What We claim as new and desire to secure by Letters Patent of the United States is:
1. A material handling device comprising frame means, a ram member secured at one end to said frame means, gate means supported from said frame means and movable between open and closed positions relative to the other end of said ram member, elevator means for raising said frame means, and control means operatively connected to said elevator means providing in said elevator means a relatively large load lifting capacity when said gate means is in its closed position and a relatively small load lifting capacity when said gate means is in its open position.
It should 2. A material handling device comprising frame means, a cantilever ram member secured at one end to said frame means, gate means supported from said frame means and actuatable between supporting and non-supporting positions relative to the free end of said ram member, load lifting means for raising and lowering said frame means, and interlocking control means operatively connected to said load lifting means and to said gate means for providing said load lifting means with a relatively large load lifting capacity when said gate means is in supporting position and with a relatively small load lifting capacity when said gate means is in its nonsupporting position.
3. A portable load handling device for use with a straddle carrier or the like having load hooks and means normally operable to elevate the load hooks, comprising a load supporting frame adapted to be engaged and elevated by the load hooks, a load engaging cantilever ram member secured at one end to said frame, a gate member pivotally attached to said frame adjacent the unsup ported end of said ram member for opening and closing movement relative thereto, drive means for opening and closing said gate member, locking means for securing said gate member when closed to said ram member, sequential control means for effecting sequential operation of said drive means and said locking means during opening and closing of said gate member, and interlocking control means responsive to the position of said gate member for preventing elevation of said load hooks when said load hooks support thereon more than a predetermined load and the said gate member is open and permitting eleva tion of said load hooks when said load hooks support thereon more than said predetermined load and the said gate member is closed.
4. For use with a vehicle having load lifting means, a load handling device comprising frame means adapted to be engaged by the load lifting means, an elongated ram member having one end secured to said frame means, a gate member secured to said frame means adjacent the normally unsupported end of said ram member and ac tuatable into open and closed positions relative to the urn supported end of said ram member for supporting said normally unsupported end when in a closed position, and interlocking control means operatively connected to the load lifting means and to the gate member for providing in the load lifting means a first load lifting capacity when said gate member is open and the second load lifting capacity which is more than the said first load lifting capacity when said gate member is closed.
5. A load handling device comprising frame means, a cantilever ram member secured to said frame means, a gate member secured to said frame means adjacent the unsupported end of said ram member and actuatable be tween open and closed positions relative to the unsup ported end of said ram member, a fluid pressure system comprising fluid drive means operatively associated with said gate member for actuating said gate member between its open and closed positions, fluid actuated means for securing said gate member in its closed position to said ram member, a main control valve for selectively directing fluid flow through said system in a first or second direction or diverting fluid flow from said system, fluid sequence control means, said control means comprising a first sequence valve connected to said main control valve for causing fluid flowing in said first direction to be directed first to said drive means and then to said securing means and a second sequence valve connected to said main control valve for causing fluid flowing in said second direction to be directed first to said securing means and then to said drive means, fluid lifting means for selectively raising and lowering said frame means, and interlocking control means for providing said lifting means with a large lifting capacity when said gate is in its closed position and a small lifting capacity when said gate is in its opened position.
6. A material handling device comprising frame means, a cantilever ram member secured to said frame means, a gate member secured to said frame means adjacent the unsupported end of said ram member and actuatable between open and closed positions relative to the unsupported end of said ram member, fluid pressure actuated means for selectively raising and lowering said frame means, and control means operatively connected to said fluid pressure actuated means providing therefor a relatively high load lifting capacity when said gate member is in its closed position and a relatively low load lifting capacity when said gate member is in its open position, said control means including relatively high and low pressure responsive valve means, and other valve means responsive to the open and closed positions of said gate member for operatively connecting said high pressure valve means with said pressure actuated means when said gate member is in one position and said low pressure valve means with said pressure actuated means when said gate member is in the other position.
7. A material handling device comprising frame means, a cantilever ram member secured to said frame means, a gate member secured to said frame means adjacent the unsupported end of said ram member and actuatable between open and closed positions relative to the unsupported end of said ram member, fluid pressure actuated means for selectively raising and lowering .said frame means, and control means operatively connected to said fluid pressure actuated means providing therefor a relatively high load lifting capacity when said gate member is in its closed position and a relatively low load lifting capacity when said gate member is in its open position, said control means including a relatively high pressure relief valve, a relatively low pressure relief valve, two position valve means arranged to selectively connect said high and low pressure relief valves to said pressure actuated means, and switch means operatively connected to said two position valve means and responsive to the position of said gate member, said switch means and two position valve means being arranged to connect said high pressure relief valve to said pressure actuated means when said gate member is closed and said low pressure valve means to said pressure actuated means when said gate member is open.
8. For use with a straddle carrier, the combination comprising supporting frame means, an elongated cantilever ram'member attached to said frame means, a gate member connected to said frame means adjacent the unsupported end of said ram member and actuatable between open and closed positions relative to the unsupported end of said ram member, fluid pressure actuated load means for elevating said frame means, a fluid system including means for selectively locking and unlocking said gate member in its closed position to said ram .member, fluid motor means connected to said gate memher for opening and closing said gate member, first valve means for causing pressure fluid to be directed first to said fluid motor means and then to said locking means for closing of the gate member and second valve means for causing pressure fluid to be directed first to said locking means and then to said fluid motor means for opening of the gate member, and interlocking control means operatively connected to said load means and to said gate member providing a relatively large load lifting capacity of said load means when said gate member is closed andlocked and a relatively small lifting capacity when said gate is unlocked and open, said control means including relatively high and low pressure responsive valve means, and other valve means responsive to the open and closed positions of said gate member for operatively connecting said high pressure valve means with said pressure actuated load means when said gate member is in one position and said low pressure valve means with said pressure actuated load means when said gate member is in the other position.
9. In combination, longitudinally extending frame means, a longitudinally extending cantilever member attached at one end to one end of said frame means, a gate member attached to the other end of said frame means and actuatable between opened and closed positions relative to the unsupported end of said cantilever member, means for selectively raising and lowering said frame means, means for locking said gate member in its closed position to said cantilever member for supporting the said unsupported end of said latter member, and control means operatively connected to said raising and lowering means for providing said raising and lowering means with a first load raising capacity when said gate member is closed and locked and a second load raising capacity less than said first capacity when said gate mem her is open.
1,178,159 Holmes Apr. 4, 1916 2,103,984 Indge Dec. 28, 1937 2,265,800 7 Connor Dec. 9, 1941 2,718,321 Westermeyer Sept. 20, 1955 2,732,083 Smith Jan. 24, 1956 2,737,393 Held Mar. 6, 1956 2,764,298 Anjeskey Sept. 25, 1956 2,975,922 Dodge Mar. 21, 1961

Claims (1)

1. A MATERIAL HANDLING DEVICE COMPRISING FRAME MEANS, A RAM MEMBER SECURED AT ONE END TO SAID FRAME MEANS, GATE MEANS SUPPORTED FROM SAID FRAME MEANS AND MOVABLE BETWEEN OPEN AND CLOSED POSITIONS RELATIVE TO THE OTHER END OF SAID RAM MEMBER, ELEVATOR MEANS FOR RAISING SAID FRAME MEANS, AND CONTROL MEANS OPERATIVELY CONNECTED TO SAID ELEVATOR MEANS PROVIDING IN SAID ELEVATOR MEANS A RELATIVELY LARGE LOAD LIFTING CAPACITY WHEN SAID
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Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1178159A (en) * 1915-10-25 1916-04-04 Alfred E Holmes Paper-holder.
US2103984A (en) * 1935-09-11 1937-12-28 Norton Co Lapping machine
US2265800A (en) * 1938-11-18 1941-12-09 Micromatic Hone Corp Variable pressure honing tool and method
US2718321A (en) * 1950-06-22 1955-09-20 Western Electric Co Apparatus for handling articles
US2732083A (en) * 1956-01-24 smith
US2737303A (en) * 1953-01-09 1956-03-06 Western Electric Co Cable reel tiering truck
US2764298A (en) * 1951-03-31 1956-09-25 Cleveland Crane Eng Apparatus for handling coiled material
US2975922A (en) * 1955-03-24 1961-03-21 Clark Equipment Co Load handling device for straddle carriers

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2732083A (en) * 1956-01-24 smith
US1178159A (en) * 1915-10-25 1916-04-04 Alfred E Holmes Paper-holder.
US2103984A (en) * 1935-09-11 1937-12-28 Norton Co Lapping machine
US2265800A (en) * 1938-11-18 1941-12-09 Micromatic Hone Corp Variable pressure honing tool and method
US2718321A (en) * 1950-06-22 1955-09-20 Western Electric Co Apparatus for handling articles
US2764298A (en) * 1951-03-31 1956-09-25 Cleveland Crane Eng Apparatus for handling coiled material
US2737303A (en) * 1953-01-09 1956-03-06 Western Electric Co Cable reel tiering truck
US2975922A (en) * 1955-03-24 1961-03-21 Clark Equipment Co Load handling device for straddle carriers

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